In the semiconductor industry, there exist various methods for applying very thin layers, in particular layers with mean thicknesses in the micrometer range, or even in the nanometer range, on surfaces. Frequently, direct coating methods that deposit a material on a surface are used. These include, for example, chemical and physical gas phase deposition, dipping methods, etc. These direct coating methods in general always coat the entire surface.
In the semiconductor industry, however, there are innumerable methods in which it is necessary to be sure not to coat the entire surface. In order to keep a coating from areas that are not to be coated, masking techniques, for example photolithography or imprint lithography, are still frequently used in the state of the art. In photo processes, however, the usual procedure is first to coat the entire surface of the wafer and then to structure it. In turn, this process therefore pertains to a complete coating of the surface, which is unacceptable for many applications. Many applications must not come into contact with the coating material at any point in time. In other applications, a brief contact with the coating material would be acceptable, but the removal of the same from the locations that are not to be coated represents a major problem. Thus, for example, structures with a large height-to-width ratio can produce a very strong capillary effect, which makes the removal of the coating material from the structures impossible. In addition, all types of masking techniques are very labor-intensive and costly, in particular since a relatively large number of process steps must be performed. An increasing number of process steps increases not only the costs, but also the susceptibility to errors.
Another approach in the semiconductor industry is the so-called microcontact printing (μCP). A technical problem lies in the fact that a μCP stamp must be adapted to transfer a material to the structures of the product wafers that are to be coated. For each new type of product wafer, a new stamp must be manufactured. In addition, the problem lies in the fact that in a first process step, a μCP stamp must be immersed in the material that is to be transferred or must be impregnated with the material from its rear side. Subsequently, an exact alignment of the μCP stamp is carried out relative to the raised structures of the product wafer. In another, third process step, the transfer of the material from the μCP stamp to the areas of the product wafer that are to be coated is carried out.